Pesticide Biochemistry and Physiology (2019) https://doi.org/10.1016/j.pestbp.2019.04.001
A Trp-574-Leu mutation in the acetolactate synthase (ALS) gene of Lithospermum arvense L. confers broad-spectrum resistance to ALS inhibitors
Qian Wanga,b, Lu'an Gea,b, Ning Zhaoa,b, Lele Zhangc, Ludan Youa,b, Dandan Wanga,b, Weitang Liua,b,⁎, Jinxin Wanga,b,⁎ a College of Plant Protection, Shandong Agricultural University, Tai'an 271018, Shandong, China b Key Laboratory of Pesticide Toxicology and Application Technology, Shandong Agricultural University, Tai'an 271018, Shandong, China c Administration Bureau of the Yellow River Delta National Nature Reserve, Dongying 257091, Shandong, China
Lithospermum arvense is a troublesome dicotyledonous winter annual weed
of wheat in China. A L. arvense population (HN01) suspected of being resistant
to acetolactate synthase (ALS) inhibitors was found in Henan Province, China.
This study aimed to testify the sensitivity of this HN01 population to eight
herbicides from 3 different modes of action, and to explore the potential
target-site-resistance mechanism to tribenuron-methyl. The whole-plant
bioassays indicated that the population was highly resistant to
tribenuron-methyl (SU, 350-fold), pyrithiobac sodium (PTB, 151-fold), pyroxsulam
(TP, 62.7-fold), florasulam (TP, 80.6-fold), and imazethapyr (IMI, 136-fold),
but was sensitive to carfentrazone-ethyl and fluroxypyr-meptyl. ALS gene
sequencing revealed that the Trp (TGG) was substituted by Leu (TTG) at codon
574 in resistant plants. In in vitro ALS assays, the concentration of
tribenuron-methyl required to inhibit 50% ALS activity (I50) for
HN01 was 117-fold greater than that required to inhibit a susceptible
population (HN05), indicating that resistance was due to reduced sensitivity of
the ALS enzyme to tribenuron-methyl. To the best of our knowledge, this is the first
report of ALS gene Trp-574-Leu amino acid mutation confer resistance to
tribenuron-methyl in L. arvense.
⁎ Corresponding authors at: College of Plant Protection, Shandong Agricultural University, Tai'an 271018, Shandong, China. E-mail addresses: liuwt@sdau.edu.cn (W. Liu), wangjx@sdau.edu.cn (J. Wang). https://doi.org/10.1016/j.pestbp.2019.04.001
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